Nonceliac Gluten Sensitivity (Intolerance) (cont.)

Jay W. Marks, MD

Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

Bhupinder S. Anand, MBBS, MD, DPHIL (OXON)

Dr. Anand received MBBS degree from Medical College Amritsar, University of Punjab. He completed his Internal Medicine residency at the Postgraduate Institute of medical Education and Research, Chandigarh, India. He was trained in the field of Gastroenterology and obtained the DPhil degree. Dr. Anand is board-certified in Internal Medicine and Gastroenterology.

What are functional intestinal disorders?

Finally, there are the "functional" intestinal disorders, disorders in which
no anatomic, histological (microscopic) or biochemical cause for the
gastrointestinal symptoms can be found, and the abnormalities are assumed to be
functional, for example, due to abnormal function of the central nervous system
(brain), gastrointestinal muscles and nerves, or intestinal secretions.
Irritable bowel syndrome (IBS) is one of these functional disorders. IBS
was at first defined broadly, but over the years its definition has become
restricted such that it is now defined as abdominal pain associated with an
alteration in bowel habit. Other non-IBS functional disorders have been
defined, for example, the occurrence of abdominal discomfort after meals.
Many patients who believe that they have gluten sensitivity have previously been
diagnosed with a functional disorder such as IBS.

Is there any
evidence that nonceliac gluten sensitivity is really a disease or condition?

You might think that it's easy to study scientifically the effects of dietary
changes and determine what dietary factors are responsible for symptoms.
It's not. It is very difficult and expensive to do rigorous studies of
diet. Finally, after years of debating the existence of nonceliac gluten
sensitivity, a scientifically sound study has been done that sheds light on the
issue. In this study, 37 patients with self-reported gluten sensitivity, well
controlled on a gluten-free diet were studied. They were given a base diet
that was gluten-free and low in FODMAPs. After observing symptoms on this base
diet, the patients were divided into two groups. In addition to the base
diet, one group received relatively pure gluten and the other group a gluten
placebo. Neither the group receiving gluten nor the group receiving
placebo developed symptoms. In other words, the group of patients with
self-reported gluten sensitivity were not gluten sensitive when tested.

Is this evidence for a placebo effect? Possibly. Could it be that
FODMAPs in the patients' usual, unrestricted diets were causing their symptoms?
Could the way in which they altered their usual diets to become gluten free have
reduced as well the FODMAPs in their diet and thereby caused the improvement in
symptoms they ascribed to gluten sensitivity? In fact, many foods high in gluten
also are high in FODMAPs, so that a gluten free diet might be expected to be
lower in FODMAPs. Are nonceliac, gluten sensitive individuals suffering
from FODMAP sensitivity? It could be. The important message to take
away from this study is that people with self-diagnosed gluten sensitivity are
not gluten sensitive. It would be useful now to do a study demonstrating
that it is the FODMAPs that are causing the symptoms in these patients.